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- Out-of-plane behavior of stone masonry walls: experimental and numerical analysisPublication . Maccarini, Helena; Vasconcelos, Graça; Rodrigues, Hugo; Ortega, Javier; Lourenço, Paulo B.Aiming at contributing to the better understanding of the out-of-plane behavior of unreinforced stone masonry structures, this paper presents the results of an experimental and numerical campaign performed on two U-shaped walls with different masonry bonds representative of Portuguese vernacular architecture. The experimental campaign included non-destructive tests for the material characterization and an out-of-plane cyclic loading test for the characterization of the out-of-plane response. A finite element numerical model was constructed, calibrated with the experimental results, which allowed performing a nonlinear parametric study to evaluate the most influential material and geometrical parameters in the out-of-plane behavior of stone masonry walls.
- Use of post-earthquake damage data to calibrate, validate and compare two seismic vulnerability assessment methods for vernacular architecturePublication . Ortega, Javier; Vasconcelos, Graça; Rodrigues, Hugo; Correia, Mariana; Ferreira, Tiago Miguel; Vicente, RomeuThe paper presents and discusses the application of two large scale seismic vulnerability assessment methods on the island of Faial in Azores (Portugal). The two methods are specifically conceived to assess the seismic vulnerability of vernacular architecture. The first method follows a classical seismic vulnerability index approach and is referred as SVIVA (Seismic Vulnerability Index for Vernacular Architecture). The second method is referred as SAVVAS (Seismic Assessment of the Vulnerability of Vernacular Architecture Structures) and it is a numerical tool intended to estimate the seismic capacity of vernacular buildings in terms of seismic load factors associated with different structural damage limit states. The main reason behind the selection of Faial Island as a case study was the availability of post-earthquake reports of the building stock after the 1998 Azores earthquake, which allowed comparing the damage scenarios obtained using both methods with the post-earthquake damage data and thus helped for the calibration and validation of the two methods. The application of both methods led to a good fit between estimated versus observed damage grades, which validated their applicability as large-scale first level approaches. Moreover, as the main outcome, the paper presents the novelties of the SAVVAS method, which had not been applied before, and discusses its main advantages, namely: no need for calibration with previous post-earthquake damage data, an enhancement of the prediction capabilities, a more individualized evaluation of the buildings and the possibility to assess the seismic performance of the building in different loading directions.
- Assessment of the influence of horizontal diaphragms on the seismic performance of vernacular buildingsPublication . Ortega, Javier; Vasconcelos, Graça; Rodrigues, Hugo; Correia, MarianaThe awareness and preservation of the vernacular heritage and traditional construction techniques and materials is crucial as a key element of cultural identity. However, vernacular architecture located in earthquake prone areas can show a particularly poor seismic performance because of inadequate construction practices resulting from economic restraints and lack of resources. The horizontal diaphragms are one of the key aspects influencing the seismic behavior of buildings because of their major role transmitting the seismic actions to the vertical resisting elements of the structure. This paper presents a numerical parametric study adopted to understand the seismic behavior and resisting mechanisms of vernacular buildings according to the type of horizontal diaphragm considered. Detailed finite element modeling and nonlinear static (pushover) analyses were used to perform the thorough parametric study aimed at the evaluation and quantification of the influence of the type of diaphragm in the seismic behavior of vernacular buildings. The reference models used for this study simulate representative rammed earth and stone masonry vernacular buildings commonly found in the South of Portugal. Therefore, this paper also contributes for a better insight of the structural behavior of vernacular earthen and stone masonry typologies under seismic loading.
- Influence of traditional earthquake-resistant techniques on the out-of-plane behaviour of stone masonry walls: Experimental and numerical assessmentPublication . Murano, Antonio; Ortega, Javier; Vasconcelos, Graça; Rodrigues, HugoThe main goal of the work is to assess the efficiency of traditional earthquake resistant solutions to improve the out-of-plane performance of stone masonry walls. Therefore, the present paper presents the results of an experimental campaign and numerical analysis performed on three stone masonry walls with a U-shaped plan configuration. Two of them were built with traditional earthquake-resistant techniques usually found in European Mediterranean area, namely steel ties and timber-laced reinforcements embedded at the corners of the walls. These techniques are specifically intended to enhance wall-to-wall connections and, thus, improve the out-of-plane behaviour of the walls. The experimental campaign included qualitative assessment procedures, non-destructive tests for the material characterization and a quasi-static test for the characterization of the out-of-plane response. Additionally, a finite element numerical model was built, calibrated with the experimental results, allowing to perform a parametric study to evaluate the influence of the number of reinforcements and geometrical configuration on the out-of-plane behaviour of stone masonry walls.
- Assessment of the efficiency of traditional earthquake resistant techniques for vernacular architecturePublication . Ortega, Javier; Vasconcelos, Graça; Rodrigues, Hugo; Correia, MarianaSpecific architectural elements can be identified in constructions located in regions frequently exposed to earthquakes. These earthquake resistant features were developed empirically by local communities to protect their built-up environment. Research in these traditional practices, resulting from a local seismic culture, is a relevant and positive approach, since it focuses on the strength of the system rather than on its weaknesses. Its integration into current vernacular building practices can help to preserve and retrofit surviving in-use examples while respecting their authenticity. The main goal of the present work is to assess numerically the efficiency of traditional earthquake resistant solutions to mitigate the seismic vulnerability of vernacular architecture. The paper thus presents the results of a detailed numerical study based on finite element modeling and nonlinear static (pushover) analysis intended to quantitatively evaluate the influence of each technique on the seismic behavior of vernacular constructions and to better understand their structural role under seismic loading.